Two goals from Scott McDonald inspired Celtic to a hard-fought victory against Kilmarnock at Rugby Park.

The Australian striker opened the scoring after 33 minutes with a smart finish from Jan Vennegoor of Hesselink's headed flick-on.

McDonald doubled the visitors' lead moments later with a diving header from Aiden McGeady's cross.

Kilmarnock reduced the deficit through Frazer Wright's header when Artur Boruc flapped at a cross, but Celtic held on.

Interview: Kilmarnock manager Jim Jefferies Interview: Celtic manager Gordon Strachan Interview: Celtic striker Scott McDonald

Kilmarnock manager Jim Jefferies brought in Ryan O'Leary for the injured David Lilley in defence.

Celtic defender Lee Naylor recovered from a virus to take his place at left-back, midfielder Jiri Jarosik got a rare SPL start with Massimo Donati dropping to the bench.

The visitors went close to taking the lead after two minutes when Scott Brown danced past a few challenges and McDonald latched onto his pass, but his shot struck the post.

Kilmarnock goalkeeper Alan Combe then produced a good save from McGeady's 18-yard shot.

Regular stoppages for free-kicks disrupted the flow of the game, with both sides struggling for fluency.

McDonald gave Celtic the lead after 33 minutes when he collected Vennegoor of Hesselink's headed flick-on and sent a right-foot shot past Combe.

The Australian striker doubled his and Celtic's tally a minute later when he headed home Aiden McGeady's cross from inside the six-yard box.

Kilmarnock reduced the deficit 10 minutes after the break when Wright headed home Gary Locke's free-kick - with Boruc flapping at the cross.

The Polish goalkeeper redeemed himself with half an hour to go when he superbly saved Colin Nish's shot from inside the 18-yard box.

Kilmarnock grew in stature after Wright's goal as Celtic's defence looked far from convincing.

Stephen McManus threw himself to block a goal-bound drive by Nish as the hosts pressed for an equaliser.

Both sides were keen to commit more players in attack as the game opened up in the final 15 minutes.

Jarosik spurned a great chance to seal the points when he scooped the ball over the bar from six yards from Hartley's free-kick.

McGeady did little to ease Celtic nerves after 89 minutes when he shot wide after a superb pass from McDonald.

Despite Kilmarnock 's spirited fightback in the second-half Celtic held on for the win and extended their lead at the top of the SPL to six points.

Kilmarnock: Combe, O'Leary, Hay, Ford, Wright, Fowler, Invincibile, Gibson, Hamill, Wales, Nish. Subs: Harpur, Locke, Dodds, Bryson, Clancy, Jarvis, Taouil.

Goals: Wright 55.

Booked: Hamill, Fowler, Bryson.

Celtic: Boruc, Caldwell, Naylor, Kennedy, McManus, Jarosik, Hartley, Scott Brown, McGeady, McDonald, Vennegoor of Hesselink. Subs: Mark Brown, Sno, O'Dea, O'Brien, Killen, Donati, Riordan.

Goals: McDonald 34, 36.

Booked: Brown, Kennedy, McGeady.

Referee: D McDonald

Att: 8,260